The aim of the barrier principle is to contain sources of radiation within nuclear installations at multiple levels. Structured like the layers of an onion, independent barriers ensure that the risk arising from radiation sources is minimised for both people and the environment.
Within Swiss nuclear power plants, the barrier principle encompasses a sequence of three physical barriers to contain the radioactive substances present in the nuclear fuel.
Barrier 1: Fuel elements
Barrier 2: Primary circuit
Barrier 3: Containment
News
Background articles
-
Series of articles on barriers 6/6: The containment holds radioactive substances in the reactor building
The reactor pressure vessel is enclosed by the containment as the third barrier. This consists of a steel primary containment and a concrete secondary containment.
-
Series of articles on barriers 5/6: The water circuit (primary circuit part 2 of 2)
With its pipelines, shut-off valves and other components, the cooling circuit, together with the reactor pressure vessel, is the second barrier for trapping radioactive substances.
-
Series of articles on barriers 4/6: The reactor pressure vessel (primary circuit part 1 of 2)
The reactor pressure vessel, together with the water’s cooling circuit, is the second barrier for trapping radioactive substances.